Hooks

ABSTRACT

A one-piece molded plastic upholstery button for receiving a loop of cord is disclosed. The button has a shank with a terminal portion which extends back toward the head of the button and which has a tongue on it that is closely spaced to a stop member to form an entrance gap to a cord receiving channel. A protuberance adjacent the bottom of the channel serves to lock the cord in place at the bottom of the channel.

United States Patent Clinch Apr. 29, 1975 HOOKS 1.339.986 5/1920 Schmidt24/2305 CR 1.494.289 5/1924 R \und H 24/2305 CR [75] lnvemo" W 1.531.2953/1925 King 24/2305 CR England 1702.946 2/1929 Powers et al 1. 24/2305TP [73] Assigneel ITW Limited, Slough 3.829.935 8/1974 Critchfield 24/90B Buckinghamshire. England Primary ExuminerD0nald A. Griffin [22] Flled'1974 Anorney. Agem. or FirnzR0bert W. Beart; .l. R. [21] Appl. No:457,514 Halvorsen [30] Foreign Application Priority Data [57] ABSTRACTMay I], 1973 United Kingdom 1. 22640/73 I A one-piece molded plasticupholstery button for re- 52 0.3. Ci. 24/2305 TP; 5/356 Ceiving a p 0fCord is disclosfid- The button has a 51 Int. Cl A44b 1/18 Shank with aterminal portion which extends back [58] Field ofSearch 24/2305 R24/2305 CR ward the head 9 the bulfion and which has a mngue 24/230 p 4/0 90 B; 5/356 on it that is closely spaced to a stop member to form anentrance gap to a cord receiving channel. A protu- [56] References Citedberance adjacent the bottom of the channel serves to i i i th b I!UNITED STATES TS lock the cord in p ace .1 e 0 cm of the channel 21[.408 l/l879 Kampf 24/2306 TP UX 2 Claims 3 Drawing Figures I[[ 18 2/.111 I 12 I HOOKS This invention concerns hooks, and in particular hookswhich are formed on members which have to fasten to loops of cord. Cordis to be understood as meaning any material which can withstand tensionbut not compression in the direction of its length.

Loops can become released from hooks if the cord becomes slack. Theproblems occurs, for example, in furniture upholstery. Upholsterybuttons lie over apertures in opposite sides of cushions and areconnected to one another by cords passing through the cushions. Thetension in the cord, when the cushion is not sat on, holds the stuffingof the cushion in place. The most convenient arrangement for assembly isto use a loop of cord, and give each button a hook.

Unfortunately sitting on the cushion relaxes the tension on the loop,and permits it to become disarranged in the hook, whereupon thesubsequent removal of a person from the cushion can release the loopfrom the hook. While it is known to give hooks fastenings to trap cordstherein, that is not convenient when the hooks have to be one-pieceplastics mouldings for economy of manufacture.

According to this invention, a hook is a onepiece plastics moulding andhas, in order, a head, a shank which has a body extending axially fromthe head then a terminal portion which extends back from the free end ofthe body towards the head, the radially inner part of the terminalportion extending as a tongue towards the head, and there being a stopprojecting from the head, lying radially outwards of the tongue, andbeing spaced therefrom by a narrow gap.

One hook constructed in accordance with this invention is describedbelow with reference to the accompanying drawing, in which:

FIG. 1 is a front elevation;

FIG. 2 is a side elevation; and

FIG. 3 is a section taken as indicated by the arrows lll-lll seen inFIG. 1.

The hook is a one piece plastics moulding and has a head 10, the shapeand purpose of which are irrelevant to the present invention. Extendingfrom the head is a shank, the body 12 of which extends axially. The freeend of the body curves smoothly to blend into a terminal portion 14 ofthe shank which extends back towards the head. The bight portion of thehook is smoothly curved, its profile as viewed in elevation in FIG. Ibeing two semi-circular arcs. The outer arc of the bight has its centreof curvature on the axis of the head, which coincides with a side of theshank, whereas the inner arc terminates on that axis. The bighttherefore diminishes in thickness from the body to the terminal portion.The radially inner part of the terminal portion 14 extends as a tongue20 towards the head. The tongue 20 is radially offset from the terminalportion towards the shank. Projecting from the head is a stop 22 whichlies radially outwards of the tongue 20 and is spaced from the tongue 20by a narrow gap 23. By "narrow is meant that the width of the gap issubstantially less than the thickness of the cord with which the hook isintended to be used, as described more fully below.

The radially outer surface 16 of the terminal shank portion 14terminates at a shoulder 18 which faces generally towards the head. Moreprecisely, the surface 18 of the shoulder faces obliquely towards thehead in a radially outward direction. The surface of the shoulder blendssmoothly into the radially outer surface of the tongue 20.

The space lying between the shank on the one side, and the terminalportion of the shank with the tongue on the other, has a protuberanceprojecting into it from the shank body. The protuberance defines afurther narrow gap between itself and the tongue, being of the sameorder of width as the gap 23. The protuberance has the effect of makingthe space 24 axially convergent/divergent.

In use the hook is used with a loop of twisted Terylene" (RTM) cordwhich is usually, but not necessarily, twisted yarn, spun from a largenumber of fine monofilaments. The diameter of the yarn is substantiallyequal to the width of the space 24, which is about two or three timeslarger than the width of the gap 23.

The loop is anchored on one side of a cushion, for example by one of thehooks described passing into an aperture in that face of the cushion,and the loop is pulled through the cushion by a hooked instrument. Withthe loop in tension, the free end of the loop is forced through the gap23, requiring the loop to be forced axially towards the head. The tongueand terminal part of the hook can flex radially inwards because of thediminishing thickness of the hook in the terminal portion. The loop canthen pass axially down the space 24 and manual tension forces it pastthe protuberance 26. Release of the tool holding the loop then causesthe cushion to expand and hold the loop in tension, securely pullingagainst the bight portion of the hook.

If someone sits on the cushion the button becomes pressed towards theloop, probably twisted and made to lie askew. It has been found with allupholstery buttons that a side of the loop tends to form a secondaryloop which rests around the hook. When the person sitting subsequentlyremoves himself, the tension in the loop, although sufficient to forcethe side of that secondary loop through the narrow gap into the space24, in fact acts in the direction away from the head, which in the hookof the present invention is also away from the opening of the gap 23.The secondary loop therefore slides from the hook. The fact that thetension in the cord moves the secondary loop away from the gap 23 arisesfrom the fact that the stop 22 lies radially outwards of the tongue; theloop has to pass axially towards the head in order to be able to passinto the space 24.

As a secondary feature the smooth oblique shape of the shoulder 18discourages the side of the secondary loop from becoming lodged, becausewhen the sitter removes himself from the cushion the shoulder causes theside of the secondary loop to slip off restoring the stable safecondition of the loop in the bight.

The hook shown can be moulded in a two-plate mould. A suitable materialfrom which to mould the hook is nylon.

I claim:

1. A molded plastic upholstery button for receiving a loop of a cordcomprising a head, a shank having a body which extends axially from saidhead and which has a terminal portion that extends back toward said headfrom a bight segment of said shank with said terminal portion beginningat said bight segment, a tongue formed on the end of said terminalportion which extends toward said head in said axial direction, a stoppositioned outwardly of said tongue and extending from said head in saidfirst direction to a point adjacent at a point adjacent said end of saidchannel to form a locking gap of a width which is less than thethickness of said cord so that said cord may thereby be secured intoplace at said end of said channel.

2. A molded plastic upholstery button as claimed in claim I wherein saidtongue has an obliquely sloping, outwardly facing shoulder and reducedthickness as said tongue approaches said entrance gap.

1. A molded plastic upholstery button for receiving a loop of a cordcomprising a head, a shank having a body which extends axially from saidhead and which has a terminal portion that extends back toward said headfrom a bight segment of said shank with said terminal portion beginningat said bight segment, a tongue formed on the end of said terminalportion which extends toward said head in said axial direction, a stoppositioned outwardly of said tongue and extending from said head in saidfirst direction to a point adjacent said tongue so as to form anentrance gap that has a width that is less than the thickness of saidcord, there being an open channel of substantially uniform thicknesswhich is of approximately the same width as said cord, said channelleading generally in said first direction from said first gap inwardlyof said tongue and said terminal portion and away from said head to theend of said channel at said bight portion and a protuberance extendingfrom said shank toward said terminal portion at a point adjacent saidend of said channel to form a locking gap of a width which is less thanthe thickness of said cord so that said cord may thereby be secured intoplace at said end of said channel.
 2. A molded plastic upholstery buttonas claimed in claim 1 wherein said tongue has an obliquely sloping,outwardly facing shoulder and reduced thickness as said tongueapproaches said entrance gap.